Here's a great article showing several different methods of setting up tow lines to rescue / assist fellow SUP paddlers. The article is on SUPConnect, a great resource for a variety of paddling info.
Read Article written by Chris Rea
|This your standard fin box with a removable fin.|
|Plastic fin with tab to hold it in place|
|Fin molded into the board (or glued)|
|Funky fin attachment|